Electric heater



Aug. 11, 1931. A. J. HOLMES 1,318,953

ELECTRIC HEATER Filed Feb. 18, 1929 2 Sheets-Sheet 1 Holmes lNZ/ENIOR ATTORN EY Z ZI-C WE zz/m' flnaggw Aug. 11, 1931.

A. J. HOLMES nmcmxcnmwsn Filed Feb. 18. 1929 2 Sheets-Sheet 2 ATTORNEY Patented Aug. 11, 1931 UNITED STATES PATENT OFFICE ANDREW J. HOME; OF AUBURN, WASHINGTON, ASSIGNOB ONE-FOURTH T0 W. B. EVERETT, OF AUBURN, WASHINGTON ELECTRIC HEATER Application fi led February 18, 1929. Serial No. 840,809.

My invention relates to improvements in electric heaters and the object of my'inv'em tion is to provide an alternating current type electric heater which is simple in construction, highly ellicient in operation and economical in its consumption of power.

Another object is to provide an electric heater that is substantially instantaneous in its delivery of heat to the liquid to he heated and one that is comparatively free from external heat losses.

Another object is to provide on electric heater wherein the water is disposed between the secondery element which is the heating element and the primary element whereby said primary element is prevented from heating to a degree that would cause the same to deteriorate. v

Another object is to provide s heater in which the iiquicl. chamber is constructed of a rust proof inetnlwhich will. resist the formstion of any electric currents set up within its walls.

A further object is to provide en electric heater having efficient enrl simple means forming and completing its magnetic circuit thereby increasing the eiiiciency of the heater.

A still further object is to provide en in cluction water heater-which is simple durable and economical construction, which is rapid and eficient in operation which will not readily out of order when in use,

@ther objects will be apparent from the following description taken in connection with the accompanying" olrewings.

in the drawings Figure l is a View in ion cituclinel section of electric heater conctructed in eccorclence with my invention suhstentisily on hrolren line l -l.'o"f Fig. 2,

being shown in nlen,

Fig, 2 is s cross section of the some subst ntieliy on broken line 2-2 of 3 is on end elevation of the bottom enol or the henten Referring to the rlrewings throughout which like reference numerals oesignete like parts, I show an electric heater embodying at central megnetic core 4 of lernineteol iron construction entirely encased within a pro" tective covering 5 of high resistance material the enris e Whichserves to exclude the water orliquid from the core, thus preventing rust and cor rosion, rest-1y lengthening the life of the core an greatly increasing the efliciency of the heater. The laminated core 4 has encl portions 6 of greater wiclth and the narrower central portion of said core between the ends 6 is surrounded by s secondary member 7 in the form of a strip of her winding or a tube or fiuteol tube which is arranged to have an electric current inclucecl therein. Bus bars 8 may he provident lost-ween the secondary and the casing 5 of the core t wherever they are necessary.

The core at with its protective housing 5 anti secondary Z? are enclosed within an outer tubular housing 9 of it highly resistant metal which forms it conduit 10 through which liquicl flow to he hosted. The tuhnlcr housing 9 is shown as rectangular in cross section with rounded; corners but it may he of any convenient shop-en -A rimary wincling ii is provided on the exterior of the housing; 9 in insuletedi relation therefrom and is rongeci to he connectecl :with on ezternei source of supply ofelectric current by rneens not shown which rney be positioned within e suitehle receptacle 12 on the exterior oi? e housing 13 which encloses the heeter.

enris 6 of the core 4; ere wicle enough so that ,1

they shut egeinst the tubular housing @on opposite sicles leaving spaces shove and be low seicl core for the passage of liquid, Two shaped ornietures oi? leniinotecl meg netic ineterinl ore disposed on opposite sides of the ler housing member 9 with their enols i5 pressed firmly against the outer sicles of said honsingg; rneinher clirectly opposite of the core snicl errnntures it serving to complete the magnetic circuit of the The nrniotures M- ore held in place by bolts 1% which genes through tingle hreclrets 1'8 on seicl srrnetures. Thehoits lo serve to ciernp the ends in of the errnetures tightly sigeinst the tube 9 to force said tuhe tightly sginst the ends 6 of the core thus forming tight connections between the parts which; carry the magnetic circuit.

Two end members 18 and 19 are rigidly all secured to the ends of the tube 9. This may be done h fianging the ends of the tube 9 as at an embeddlng the flanged ends into the end plates in the process of casting the end lates or it may be done by brazing or Welding the tube to the end plates. The two end plates 18 and 19 are spaced from the ends of the core 4 and armatures 14 and have lugs 21 that engage with said ends of said core 4 and armatures 14. This affords spaces at the ends of the heater, tends to prevent elec trical hum in the heater when in operation and helps hold the core and armature in place. The lower end plate 19 is provided with a central water inlet opening 22 for the reception of a water circulation ipe 23. The rapper end plate 18 has a centrally 1positione hub 24- aftording an opening arge enough so that the core and secondary may be withdrawn therethrough and has a screw cap 25 forming a closure for said hub and adapted to be connected with a water outlet pipe 26.

lhe sides of the housing are preferably in the form of two half shells 13 which rest on studs 27 on the end plates 18 and 19 and are secured in place by bolts 28 which pass crosswise through said half shells thus forming a very quickly and easily demon strated structure.

The entire heater is quickly and easily assembled or taken apart thus reducing cost of production and making the parts easily accessible for the purpose of cleaning or repairs should the same be necessary.

In operation of this heater, the same is installed, preferably in an upright position, so that liquid, as water, may be free to flow therethrough and current from an external source is supplied to the primary coil 11. This current flowing in the primary 11 induces a current in the secondary 7 causing the lines of magnetic flux to be cut thereby producing a great volume of electric energy within said secondary 7 which produces a large quantity of heat units therein resulting in a substantially instantaneous heating of the parts within the chamber 10 and a correspondin 1y uick heating of the liquid within said chem er. As soon as the liquid is heated it will tend to rise, setting up a circulation through the heater in the usual manner.

This heater is substantially instantaneous in its heating up operation and is capable of developing a high efiiciency in proportion to the power used. The high resistance covering protects the laminated metal parts from direct contact with the liquid thus preventin corrosion and rapid deterioration.

e metal of the tubing 9 is of such a character as to resist the loss of power through the formation of currents therein and is preferably quite thin in order to keep the break in the magnetic circuit between the parts 6 and 15 as small as possible. The metal casing 5, enclosing the metal core 4, has as its principal object the protection of said core rom corrosion and is itself, of course, noncorrodible. In certain cases this casing 5 may be utilized as the secondary circuit or as I.

an auxiliary thereto, by permitting currents to be formed therein to heat it and the water in which it is submerged.

The foregoing description and accompanying drawings clearly disclose a preferred embodiment of my invention but it will be understood that this disclosure is merely illustrative and that changes in form, shape and arrangement of parts may be made within the scope and spirit of the following claims.

IVhat I claim is 1. In an electric heater, a tubular liquid chamber formed of high resistance metal, a core of magnetic material disposed Within said chamber, a protective covering of metal entirely enclosing said core, and secondary coil means disposed within said chamber and surrounding said core.

2. In an electric heater, a tubular liquid chamber, a core of magnetic material within said chamber, a liquid tight metal covering for said core, said covering and the walls of said chamber being of non-corrosive metal, a primary'coil surrounding said chamber, and a secondary disposed within said chambe and surrounding said core.

3. In an induction electric water heater, a tubular liquid chamber, a core of magnetic material within said chamber, a primary coil surrounding said chamber, a secondary disposed within said chamber and extending around said core, and armatures magnetically connected with the ends of said core and extending around the primary coil to complete the magnetic circuit.

4. In an induction electric water heater,

' a tubular liquid chamber, a core of magnetic mary coil.

5. The apparatus as described in claim 4, in which the ends of the tubular liquid chamber have liquid tight connection with end plates which are adapted for connection with liquid circulating means.

In testimony whereof I afiix my signature.

ANDREW J. HOLMES. 

